The introduction of digital cinema and the development of true three-dimensional (“3D”) or virtual 3D content has created new standards for sound, such as the incorporation of multiple channels of audio to allow for greater creativity for content creators and a more enveloping and realistic auditory experience for audiences. Expanding beyond traditional speaker feeds and channel-based audio as a means for distributing spatial audio is of critical importance, and there has been considerable interest in a model-based audio description that allows the listener to select a desired playback configuration with the audio rendered specifically for their chosen configuration. The spatial presentation of sound utilizes audio objects, which are audio signals with associated parametric source descriptions of apparent source position (e.g., 3D coordinates), apparent source width, and other parameters. Further advancements include a next generation spatial audio (also referred to as “adaptive audio”) format that has been developed which comprises a mix of audio objects and traditional channel-based speaker feeds, along with positional metadata for the audio objects. In a spatial audio decoder, the channels are sent directly to their associated speakers or down-mixed to an existing speaker set, and audio objects are rendered by the decoder in a flexible (adaptive) manner. The parametric source description associated with each object, such as a positional trajectory in 3D space, is taken as an input along with the number and positions of speakers connected to the decoder. The renderer then utilizes certain algorithms, such as a panning law, to distribute the audio associated with each object (“object-based audio”) across the attached set of speakers. The authored spatial intent of each object is thus optimally presented over the specific speaker configuration that is present in the listening room.
With the introduction of adaptive audio systems, the number of required amplifier channels has greatly increased (e.g., up to 32 or more channels), thereby necessitating the installation of new amplifiers and/or higher channel-count amplifiers. Additionally, because each surround loudspeaker requires its own amplification channel, upgrading the sound systems in existing theaters requires extensive modifications (e.g., eliminating parallel combinations of speakers in favor of point-to-point individual wiring). FIG. 1 is a diagram that illustrates a typical amplification approach for multi-channel applications using existing technology. As shown in FIG. 1, a system having nine channels 102, with nine individual speakers or sets of speakers 108 requires nine individual amplifiers 104, nine individual cable runs 106, and five or more power supplies (inside the two-channel amplifiers). Such a system represents a typical amplifier-speaker layout as can be found in a modern movie theater playing surround-sound audio, and illustrates the amount of hardware and infrastructure currently used in such systems. Changing the amplification and wiring infrastructure to accommodate greater than the current supported topography within theaters is a costly endeavor and replacing existing audio amplifiers and cabling that are perfectly operational is not an efficient method of upgrading to accommodate newer audio formats. In many instances, audio amplifiers used in medium to large-scale surround sound environments are quality devices with capable output power, but simply do not have enough channels to support sophisticated multi-channel systems, such as the Dolby Atmos system.
What is needed, therefore, is an intelligent audio interface system that provides flexible, cost-effective power distribution, while also adding features found in advanced audio playback applications. What is further needed is a system that provides an effective upgrade path for home and professional listening environments to play advanced audio content with minimal installation and retrofit cost.
The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves also may be inventions. Dolby, Dolby Digital Plus, and Atmos are trademarks of Dolby Laboratories Licensing Corporation.